1 /* 2 * CS4270 ALSA SoC (ASoC) codec driver 3 * 4 * Author: Timur Tabi <timur@freescale.com> 5 * 6 * Copyright 2007-2009 Freescale Semiconductor, Inc. This file is licensed 7 * under the terms of the GNU General Public License version 2. This 8 * program is licensed "as is" without any warranty of any kind, whether 9 * express or implied. 10 * 11 * This is an ASoC device driver for the Cirrus Logic CS4270 codec. 12 * 13 * Current features/limitations: 14 * 15 * 1) Software mode is supported. Stand-alone mode is not supported. 16 * 2) Only I2C is supported, not SPI 17 * 3) Only Master mode is supported, not Slave. 18 * 4) The machine driver's 'startup' function must call 19 * cs4270_set_dai_sysclk() with the value of MCLK. 20 * 5) Only I2S and left-justified modes are supported 21 * 6) Power management is not supported 22 * 7) The only supported control is volume and hardware mute (if enabled) 23 */ 24 25 #include <linux/module.h> 26 #include <linux/platform_device.h> 27 #include <sound/core.h> 28 #include <sound/soc.h> 29 #include <sound/initval.h> 30 #include <linux/i2c.h> 31 32 #include "cs4270.h" 33 34 /* 35 * The codec isn't really big-endian or little-endian, since the I2S 36 * interface requires data to be sent serially with the MSbit first. 37 * However, to support BE and LE I2S devices, we specify both here. That 38 * way, ALSA will always match the bit patterns. 39 */ 40 #define CS4270_FORMATS (SNDRV_PCM_FMTBIT_S8 | \ 41 SNDRV_PCM_FMTBIT_S16_LE | SNDRV_PCM_FMTBIT_S16_BE | \ 42 SNDRV_PCM_FMTBIT_S18_3LE | SNDRV_PCM_FMTBIT_S18_3BE | \ 43 SNDRV_PCM_FMTBIT_S20_3LE | SNDRV_PCM_FMTBIT_S20_3BE | \ 44 SNDRV_PCM_FMTBIT_S24_3LE | SNDRV_PCM_FMTBIT_S24_3BE | \ 45 SNDRV_PCM_FMTBIT_S24_LE | SNDRV_PCM_FMTBIT_S24_BE) 46 47 /* CS4270 registers addresses */ 48 #define CS4270_CHIPID 0x01 /* Chip ID */ 49 #define CS4270_PWRCTL 0x02 /* Power Control */ 50 #define CS4270_MODE 0x03 /* Mode Control */ 51 #define CS4270_FORMAT 0x04 /* Serial Format, ADC/DAC Control */ 52 #define CS4270_TRANS 0x05 /* Transition Control */ 53 #define CS4270_MUTE 0x06 /* Mute Control */ 54 #define CS4270_VOLA 0x07 /* DAC Channel A Volume Control */ 55 #define CS4270_VOLB 0x08 /* DAC Channel B Volume Control */ 56 57 #define CS4270_FIRSTREG 0x01 58 #define CS4270_LASTREG 0x08 59 #define CS4270_NUMREGS (CS4270_LASTREG - CS4270_FIRSTREG + 1) 60 61 /* Bit masks for the CS4270 registers */ 62 #define CS4270_CHIPID_ID 0xF0 63 #define CS4270_CHIPID_REV 0x0F 64 #define CS4270_PWRCTL_FREEZE 0x80 65 #define CS4270_PWRCTL_PDN_ADC 0x20 66 #define CS4270_PWRCTL_PDN_DAC 0x02 67 #define CS4270_PWRCTL_PDN 0x01 68 #define CS4270_MODE_SPEED_MASK 0x30 69 #define CS4270_MODE_1X 0x00 70 #define CS4270_MODE_2X 0x10 71 #define CS4270_MODE_4X 0x20 72 #define CS4270_MODE_SLAVE 0x30 73 #define CS4270_MODE_DIV_MASK 0x0E 74 #define CS4270_MODE_DIV1 0x00 75 #define CS4270_MODE_DIV15 0x02 76 #define CS4270_MODE_DIV2 0x04 77 #define CS4270_MODE_DIV3 0x06 78 #define CS4270_MODE_DIV4 0x08 79 #define CS4270_MODE_POPGUARD 0x01 80 #define CS4270_FORMAT_FREEZE_A 0x80 81 #define CS4270_FORMAT_FREEZE_B 0x40 82 #define CS4270_FORMAT_LOOPBACK 0x20 83 #define CS4270_FORMAT_DAC_MASK 0x18 84 #define CS4270_FORMAT_DAC_LJ 0x00 85 #define CS4270_FORMAT_DAC_I2S 0x08 86 #define CS4270_FORMAT_DAC_RJ16 0x18 87 #define CS4270_FORMAT_DAC_RJ24 0x10 88 #define CS4270_FORMAT_ADC_MASK 0x01 89 #define CS4270_FORMAT_ADC_LJ 0x00 90 #define CS4270_FORMAT_ADC_I2S 0x01 91 #define CS4270_TRANS_ONE_VOL 0x80 92 #define CS4270_TRANS_SOFT 0x40 93 #define CS4270_TRANS_ZERO 0x20 94 #define CS4270_TRANS_INV_ADC_A 0x08 95 #define CS4270_TRANS_INV_ADC_B 0x10 96 #define CS4270_TRANS_INV_DAC_A 0x02 97 #define CS4270_TRANS_INV_DAC_B 0x04 98 #define CS4270_TRANS_DEEMPH 0x01 99 #define CS4270_MUTE_AUTO 0x20 100 #define CS4270_MUTE_ADC_A 0x08 101 #define CS4270_MUTE_ADC_B 0x10 102 #define CS4270_MUTE_POLARITY 0x04 103 #define CS4270_MUTE_DAC_A 0x01 104 #define CS4270_MUTE_DAC_B 0x02 105 106 /* Private data for the CS4270 */ 107 struct cs4270_private { 108 struct snd_soc_codec codec; 109 u8 reg_cache[CS4270_NUMREGS]; 110 unsigned int mclk; /* Input frequency of the MCLK pin */ 111 unsigned int mode; /* The mode (I2S or left-justified) */ 112 unsigned int slave_mode; 113 }; 114 115 /** 116 * struct cs4270_mode_ratios - clock ratio tables 117 * @ratio: the ratio of MCLK to the sample rate 118 * @speed_mode: the Speed Mode bits to set in the Mode Control register for 119 * this ratio 120 * @mclk: the Ratio Select bits to set in the Mode Control register for this 121 * ratio 122 * 123 * The data for this chart is taken from Table 5 of the CS4270 reference 124 * manual. 125 * 126 * This table is used to determine how to program the Mode Control register. 127 * It is also used by cs4270_set_dai_sysclk() to tell ALSA which sampling 128 * rates the CS4270 currently supports. 129 * 130 * @speed_mode is the corresponding bit pattern to be written to the 131 * MODE bits of the Mode Control Register 132 * 133 * @mclk is the corresponding bit pattern to be wirten to the MCLK bits of 134 * the Mode Control Register. 135 * 136 * In situations where a single ratio is represented by multiple speed 137 * modes, we favor the slowest speed. E.g, for a ratio of 128, we pick 138 * double-speed instead of quad-speed. However, the CS4270 errata states 139 * that divide-By-1.5 can cause failures, so we avoid that mode where 140 * possible. 141 * 142 * Errata: There is an errata for the CS4270 where divide-by-1.5 does not 143 * work if Vd is 3.3V. If this effects you, select the 144 * CONFIG_SND_SOC_CS4270_VD33_ERRATA Kconfig option, and the driver will 145 * never select any sample rates that require divide-by-1.5. 146 */ 147 struct cs4270_mode_ratios { 148 unsigned int ratio; 149 u8 speed_mode; 150 u8 mclk; 151 }; 152 153 static struct cs4270_mode_ratios cs4270_mode_ratios[] = { 154 {64, CS4270_MODE_4X, CS4270_MODE_DIV1}, 155 #ifndef CONFIG_SND_SOC_CS4270_VD33_ERRATA 156 {96, CS4270_MODE_4X, CS4270_MODE_DIV15}, 157 #endif 158 {128, CS4270_MODE_2X, CS4270_MODE_DIV1}, 159 {192, CS4270_MODE_4X, CS4270_MODE_DIV3}, 160 {256, CS4270_MODE_1X, CS4270_MODE_DIV1}, 161 {384, CS4270_MODE_2X, CS4270_MODE_DIV3}, 162 {512, CS4270_MODE_1X, CS4270_MODE_DIV2}, 163 {768, CS4270_MODE_1X, CS4270_MODE_DIV3}, 164 {1024, CS4270_MODE_1X, CS4270_MODE_DIV4} 165 }; 166 167 /* The number of MCLK/LRCK ratios supported by the CS4270 */ 168 #define NUM_MCLK_RATIOS ARRAY_SIZE(cs4270_mode_ratios) 169 170 /** 171 * cs4270_set_dai_sysclk - determine the CS4270 samples rates. 172 * @codec_dai: the codec DAI 173 * @clk_id: the clock ID (ignored) 174 * @freq: the MCLK input frequency 175 * @dir: the clock direction (ignored) 176 * 177 * This function is used to tell the codec driver what the input MCLK 178 * frequency is. 179 * 180 * The value of MCLK is used to determine which sample rates are supported 181 * by the CS4270. The ratio of MCLK / Fs must be equal to one of nine 182 * supported values - 64, 96, 128, 192, 256, 384, 512, 768, and 1024. 183 * 184 * This function calculates the nine ratios and determines which ones match 185 * a standard sample rate. If there's a match, then it is added to the list 186 * of supported sample rates. 187 * 188 * This function must be called by the machine driver's 'startup' function, 189 * otherwise the list of supported sample rates will not be available in 190 * time for ALSA. 191 */ 192 static int cs4270_set_dai_sysclk(struct snd_soc_dai *codec_dai, 193 int clk_id, unsigned int freq, int dir) 194 { 195 struct snd_soc_codec *codec = codec_dai->codec; 196 struct cs4270_private *cs4270 = codec->private_data; 197 unsigned int rates = 0; 198 unsigned int rate_min = -1; 199 unsigned int rate_max = 0; 200 unsigned int i; 201 202 cs4270->mclk = freq; 203 204 for (i = 0; i < NUM_MCLK_RATIOS; i++) { 205 unsigned int rate = freq / cs4270_mode_ratios[i].ratio; 206 rates |= snd_pcm_rate_to_rate_bit(rate); 207 if (rate < rate_min) 208 rate_min = rate; 209 if (rate > rate_max) 210 rate_max = rate; 211 } 212 /* FIXME: soc should support a rate list */ 213 rates &= ~SNDRV_PCM_RATE_KNOT; 214 215 if (!rates) { 216 dev_err(codec->dev, "could not find a valid sample rate\n"); 217 return -EINVAL; 218 } 219 220 codec_dai->playback.rates = rates; 221 codec_dai->playback.rate_min = rate_min; 222 codec_dai->playback.rate_max = rate_max; 223 224 codec_dai->capture.rates = rates; 225 codec_dai->capture.rate_min = rate_min; 226 codec_dai->capture.rate_max = rate_max; 227 228 return 0; 229 } 230 231 /** 232 * cs4270_set_dai_fmt - configure the codec for the selected audio format 233 * @codec_dai: the codec DAI 234 * @format: a SND_SOC_DAIFMT_x value indicating the data format 235 * 236 * This function takes a bitmask of SND_SOC_DAIFMT_x bits and programs the 237 * codec accordingly. 238 * 239 * Currently, this function only supports SND_SOC_DAIFMT_I2S and 240 * SND_SOC_DAIFMT_LEFT_J. The CS4270 codec also supports right-justified 241 * data for playback only, but ASoC currently does not support different 242 * formats for playback vs. record. 243 */ 244 static int cs4270_set_dai_fmt(struct snd_soc_dai *codec_dai, 245 unsigned int format) 246 { 247 struct snd_soc_codec *codec = codec_dai->codec; 248 struct cs4270_private *cs4270 = codec->private_data; 249 int ret = 0; 250 251 /* set DAI format */ 252 switch (format & SND_SOC_DAIFMT_FORMAT_MASK) { 253 case SND_SOC_DAIFMT_I2S: 254 case SND_SOC_DAIFMT_LEFT_J: 255 cs4270->mode = format & SND_SOC_DAIFMT_FORMAT_MASK; 256 break; 257 default: 258 dev_err(codec->dev, "invalid dai format\n"); 259 ret = -EINVAL; 260 } 261 262 /* set master/slave audio interface */ 263 switch (format & SND_SOC_DAIFMT_MASTER_MASK) { 264 case SND_SOC_DAIFMT_CBS_CFS: 265 cs4270->slave_mode = 1; 266 break; 267 case SND_SOC_DAIFMT_CBM_CFM: 268 cs4270->slave_mode = 0; 269 break; 270 default: 271 /* all other modes are unsupported by the hardware */ 272 ret = -EINVAL; 273 } 274 275 return ret; 276 } 277 278 /** 279 * cs4270_fill_cache - pre-fill the CS4270 register cache. 280 * @codec: the codec for this CS4270 281 * 282 * This function fills in the CS4270 register cache by reading the register 283 * values from the hardware. 284 * 285 * This CS4270 registers are cached to avoid excessive I2C I/O operations. 286 * After the initial read to pre-fill the cache, the CS4270 never updates 287 * the register values, so we won't have a cache coherency problem. 288 * 289 * We use the auto-increment feature of the CS4270 to read all registers in 290 * one shot. 291 */ 292 static int cs4270_fill_cache(struct snd_soc_codec *codec) 293 { 294 u8 *cache = codec->reg_cache; 295 struct i2c_client *i2c_client = codec->control_data; 296 s32 length; 297 298 length = i2c_smbus_read_i2c_block_data(i2c_client, 299 CS4270_FIRSTREG | 0x80, CS4270_NUMREGS, cache); 300 301 if (length != CS4270_NUMREGS) { 302 dev_err(codec->dev, "i2c read failure, addr=0x%x\n", 303 i2c_client->addr); 304 return -EIO; 305 } 306 307 return 0; 308 } 309 310 /** 311 * cs4270_read_reg_cache - read from the CS4270 register cache. 312 * @codec: the codec for this CS4270 313 * @reg: the register to read 314 * 315 * This function returns the value for a given register. It reads only from 316 * the register cache, not the hardware itself. 317 * 318 * This CS4270 registers are cached to avoid excessive I2C I/O operations. 319 * After the initial read to pre-fill the cache, the CS4270 never updates 320 * the register values, so we won't have a cache coherency problem. 321 */ 322 static unsigned int cs4270_read_reg_cache(struct snd_soc_codec *codec, 323 unsigned int reg) 324 { 325 u8 *cache = codec->reg_cache; 326 327 if ((reg < CS4270_FIRSTREG) || (reg > CS4270_LASTREG)) 328 return -EIO; 329 330 return cache[reg - CS4270_FIRSTREG]; 331 } 332 333 /** 334 * cs4270_i2c_write - write to a CS4270 register via the I2C bus. 335 * @codec: the codec for this CS4270 336 * @reg: the register to write 337 * @value: the value to write to the register 338 * 339 * This function writes the given value to the given CS4270 register, and 340 * also updates the register cache. 341 * 342 * Note that we don't use the hw_write function pointer of snd_soc_codec. 343 * That's because it's too clunky: the hw_write_t prototype does not match 344 * i2c_smbus_write_byte_data(), and it's just another layer of overhead. 345 */ 346 static int cs4270_i2c_write(struct snd_soc_codec *codec, unsigned int reg, 347 unsigned int value) 348 { 349 u8 *cache = codec->reg_cache; 350 351 if ((reg < CS4270_FIRSTREG) || (reg > CS4270_LASTREG)) 352 return -EIO; 353 354 /* Only perform an I2C operation if the new value is different */ 355 if (cache[reg - CS4270_FIRSTREG] != value) { 356 struct i2c_client *client = codec->control_data; 357 if (i2c_smbus_write_byte_data(client, reg, value)) { 358 dev_err(codec->dev, "i2c write failed\n"); 359 return -EIO; 360 } 361 362 /* We've written to the hardware, so update the cache */ 363 cache[reg - CS4270_FIRSTREG] = value; 364 } 365 366 return 0; 367 } 368 369 /** 370 * cs4270_hw_params - program the CS4270 with the given hardware parameters. 371 * @substream: the audio stream 372 * @params: the hardware parameters to set 373 * @dai: the SOC DAI (ignored) 374 * 375 * This function programs the hardware with the values provided. 376 * Specifically, the sample rate and the data format. 377 * 378 * The .ops functions are used to provide board-specific data, like input 379 * frequencies, to this driver. This function takes that information, 380 * combines it with the hardware parameters provided, and programs the 381 * hardware accordingly. 382 */ 383 static int cs4270_hw_params(struct snd_pcm_substream *substream, 384 struct snd_pcm_hw_params *params, 385 struct snd_soc_dai *dai) 386 { 387 struct snd_soc_pcm_runtime *rtd = substream->private_data; 388 struct snd_soc_device *socdev = rtd->socdev; 389 struct snd_soc_codec *codec = socdev->card->codec; 390 struct cs4270_private *cs4270 = codec->private_data; 391 int ret; 392 unsigned int i; 393 unsigned int rate; 394 unsigned int ratio; 395 int reg; 396 397 /* Figure out which MCLK/LRCK ratio to use */ 398 399 rate = params_rate(params); /* Sampling rate, in Hz */ 400 ratio = cs4270->mclk / rate; /* MCLK/LRCK ratio */ 401 402 for (i = 0; i < NUM_MCLK_RATIOS; i++) { 403 if (cs4270_mode_ratios[i].ratio == ratio) 404 break; 405 } 406 407 if (i == NUM_MCLK_RATIOS) { 408 /* We did not find a matching ratio */ 409 dev_err(codec->dev, "could not find matching ratio\n"); 410 return -EINVAL; 411 } 412 413 /* Set the sample rate */ 414 415 reg = snd_soc_read(codec, CS4270_MODE); 416 reg &= ~(CS4270_MODE_SPEED_MASK | CS4270_MODE_DIV_MASK); 417 reg |= cs4270_mode_ratios[i].mclk; 418 419 if (cs4270->slave_mode) 420 reg |= CS4270_MODE_SLAVE; 421 else 422 reg |= cs4270_mode_ratios[i].speed_mode; 423 424 ret = snd_soc_write(codec, CS4270_MODE, reg); 425 if (ret < 0) { 426 dev_err(codec->dev, "i2c write failed\n"); 427 return ret; 428 } 429 430 /* Set the DAI format */ 431 432 reg = snd_soc_read(codec, CS4270_FORMAT); 433 reg &= ~(CS4270_FORMAT_DAC_MASK | CS4270_FORMAT_ADC_MASK); 434 435 switch (cs4270->mode) { 436 case SND_SOC_DAIFMT_I2S: 437 reg |= CS4270_FORMAT_DAC_I2S | CS4270_FORMAT_ADC_I2S; 438 break; 439 case SND_SOC_DAIFMT_LEFT_J: 440 reg |= CS4270_FORMAT_DAC_LJ | CS4270_FORMAT_ADC_LJ; 441 break; 442 default: 443 dev_err(codec->dev, "unknown dai format\n"); 444 return -EINVAL; 445 } 446 447 ret = snd_soc_write(codec, CS4270_FORMAT, reg); 448 if (ret < 0) { 449 dev_err(codec->dev, "i2c write failed\n"); 450 return ret; 451 } 452 453 return ret; 454 } 455 456 /** 457 * cs4270_mute - enable/disable the CS4270 external mute 458 * @dai: the SOC DAI 459 * @mute: 0 = disable mute, 1 = enable mute 460 * 461 * This function toggles the mute bits in the MUTE register. The CS4270's 462 * mute capability is intended for external muting circuitry, so if the 463 * board does not have the MUTEA or MUTEB pins connected to such circuitry, 464 * then this function will do nothing. 465 */ 466 static int cs4270_mute(struct snd_soc_dai *dai, int mute) 467 { 468 struct snd_soc_codec *codec = dai->codec; 469 int reg6; 470 471 reg6 = snd_soc_read(codec, CS4270_MUTE); 472 473 if (mute) 474 reg6 |= CS4270_MUTE_DAC_A | CS4270_MUTE_DAC_B; 475 else 476 reg6 &= ~(CS4270_MUTE_DAC_A | CS4270_MUTE_DAC_B); 477 478 return snd_soc_write(codec, CS4270_MUTE, reg6); 479 } 480 481 /* A list of non-DAPM controls that the CS4270 supports */ 482 static const struct snd_kcontrol_new cs4270_snd_controls[] = { 483 SOC_DOUBLE_R("Master Playback Volume", 484 CS4270_VOLA, CS4270_VOLB, 0, 0xFF, 1), 485 SOC_SINGLE("Digital Sidetone Switch", CS4270_FORMAT, 5, 1, 0), 486 SOC_SINGLE("Soft Ramp Switch", CS4270_TRANS, 6, 1, 0), 487 SOC_SINGLE("Zero Cross Switch", CS4270_TRANS, 5, 1, 0), 488 SOC_SINGLE("Popguard Switch", CS4270_MODE, 0, 1, 1), 489 SOC_SINGLE("Auto-Mute Switch", CS4270_MUTE, 5, 1, 0), 490 SOC_DOUBLE("Master Capture Switch", CS4270_MUTE, 3, 4, 1, 0) 491 }; 492 493 /* 494 * cs4270_codec - global variable to store codec for the ASoC probe function 495 * 496 * If struct i2c_driver had a private_data field, we wouldn't need to use 497 * cs4270_codec. This is the only way to pass the codec structure from 498 * cs4270_i2c_probe() to cs4270_probe(). Unfortunately, there is no good 499 * way to synchronize these two functions. cs4270_i2c_probe() can be called 500 * multiple times before cs4270_probe() is called even once. So for now, we 501 * also only allow cs4270_i2c_probe() to be run once. That means that we do 502 * not support more than one cs4270 device in the system, at least for now. 503 */ 504 static struct snd_soc_codec *cs4270_codec; 505 506 static struct snd_soc_dai_ops cs4270_dai_ops = { 507 .hw_params = cs4270_hw_params, 508 .set_sysclk = cs4270_set_dai_sysclk, 509 .set_fmt = cs4270_set_dai_fmt, 510 .digital_mute = cs4270_mute, 511 }; 512 513 struct snd_soc_dai cs4270_dai = { 514 .name = "cs4270", 515 .playback = { 516 .stream_name = "Playback", 517 .channels_min = 1, 518 .channels_max = 2, 519 .rates = 0, 520 .formats = CS4270_FORMATS, 521 }, 522 .capture = { 523 .stream_name = "Capture", 524 .channels_min = 1, 525 .channels_max = 2, 526 .rates = 0, 527 .formats = CS4270_FORMATS, 528 }, 529 .ops = &cs4270_dai_ops, 530 }; 531 EXPORT_SYMBOL_GPL(cs4270_dai); 532 533 /** 534 * cs4270_probe - ASoC probe function 535 * @pdev: platform device 536 * 537 * This function is called when ASoC has all the pieces it needs to 538 * instantiate a sound driver. 539 */ 540 static int cs4270_probe(struct platform_device *pdev) 541 { 542 struct snd_soc_device *socdev = platform_get_drvdata(pdev); 543 struct snd_soc_codec *codec = cs4270_codec; 544 unsigned int i; 545 int ret; 546 547 /* Connect the codec to the socdev. snd_soc_new_pcms() needs this. */ 548 socdev->card->codec = codec; 549 550 /* Register PCMs */ 551 ret = snd_soc_new_pcms(socdev, SNDRV_DEFAULT_IDX1, SNDRV_DEFAULT_STR1); 552 if (ret < 0) { 553 dev_err(codec->dev, "failed to create pcms\n"); 554 return ret; 555 } 556 557 /* Add the non-DAPM controls */ 558 for (i = 0; i < ARRAY_SIZE(cs4270_snd_controls); i++) { 559 struct snd_kcontrol *kctrl; 560 561 kctrl = snd_soc_cnew(&cs4270_snd_controls[i], codec, NULL); 562 if (!kctrl) { 563 dev_err(codec->dev, "error creating control '%s'\n", 564 cs4270_snd_controls[i].name); 565 ret = -ENOMEM; 566 goto error_free_pcms; 567 } 568 569 ret = snd_ctl_add(codec->card, kctrl); 570 if (ret < 0) { 571 dev_err(codec->dev, "error adding control '%s'\n", 572 cs4270_snd_controls[i].name); 573 goto error_free_pcms; 574 } 575 } 576 577 /* And finally, register the socdev */ 578 ret = snd_soc_init_card(socdev); 579 if (ret < 0) { 580 dev_err(codec->dev, "failed to register card\n"); 581 goto error_free_pcms; 582 } 583 584 return 0; 585 586 error_free_pcms: 587 snd_soc_free_pcms(socdev); 588 589 return ret; 590 } 591 592 /** 593 * cs4270_remove - ASoC remove function 594 * @pdev: platform device 595 * 596 * This function is the counterpart to cs4270_probe(). 597 */ 598 static int cs4270_remove(struct platform_device *pdev) 599 { 600 struct snd_soc_device *socdev = platform_get_drvdata(pdev); 601 602 snd_soc_free_pcms(socdev); 603 604 return 0; 605 }; 606 607 /** 608 * cs4270_i2c_probe - initialize the I2C interface of the CS4270 609 * @i2c_client: the I2C client object 610 * @id: the I2C device ID (ignored) 611 * 612 * This function is called whenever the I2C subsystem finds a device that 613 * matches the device ID given via a prior call to i2c_add_driver(). 614 */ 615 static int cs4270_i2c_probe(struct i2c_client *i2c_client, 616 const struct i2c_device_id *id) 617 { 618 struct snd_soc_codec *codec; 619 struct cs4270_private *cs4270; 620 unsigned int reg; 621 int ret; 622 623 /* For now, we only support one cs4270 device in the system. See the 624 * comment for cs4270_codec. 625 */ 626 if (cs4270_codec) { 627 dev_err(&i2c_client->dev, "ignoring CS4270 at addr %X\n", 628 i2c_client->addr); 629 dev_err(&i2c_client->dev, "only one per board allowed\n"); 630 /* Should we return something other than ENODEV here? */ 631 return -ENODEV; 632 } 633 634 /* Verify that we have a CS4270 */ 635 636 ret = i2c_smbus_read_byte_data(i2c_client, CS4270_CHIPID); 637 if (ret < 0) { 638 dev_err(&i2c_client->dev, "failed to read i2c at addr %X\n", 639 i2c_client->addr); 640 return ret; 641 } 642 /* The top four bits of the chip ID should be 1100. */ 643 if ((ret & 0xF0) != 0xC0) { 644 dev_err(&i2c_client->dev, "device at addr %X is not a CS4270\n", 645 i2c_client->addr); 646 return -ENODEV; 647 } 648 649 dev_info(&i2c_client->dev, "found device at i2c address %X\n", 650 i2c_client->addr); 651 dev_info(&i2c_client->dev, "hardware revision %X\n", ret & 0xF); 652 653 /* Allocate enough space for the snd_soc_codec structure 654 and our private data together. */ 655 cs4270 = kzalloc(sizeof(struct cs4270_private), GFP_KERNEL); 656 if (!cs4270) { 657 dev_err(&i2c_client->dev, "could not allocate codec\n"); 658 return -ENOMEM; 659 } 660 codec = &cs4270->codec; 661 662 mutex_init(&codec->mutex); 663 INIT_LIST_HEAD(&codec->dapm_widgets); 664 INIT_LIST_HEAD(&codec->dapm_paths); 665 666 codec->dev = &i2c_client->dev; 667 codec->name = "CS4270"; 668 codec->owner = THIS_MODULE; 669 codec->dai = &cs4270_dai; 670 codec->num_dai = 1; 671 codec->private_data = cs4270; 672 codec->control_data = i2c_client; 673 codec->read = cs4270_read_reg_cache; 674 codec->write = cs4270_i2c_write; 675 codec->reg_cache = cs4270->reg_cache; 676 codec->reg_cache_size = CS4270_NUMREGS; 677 678 /* The I2C interface is set up, so pre-fill our register cache */ 679 680 ret = cs4270_fill_cache(codec); 681 if (ret < 0) { 682 dev_err(&i2c_client->dev, "failed to fill register cache\n"); 683 goto error_free_codec; 684 } 685 686 /* Disable auto-mute. This feature appears to be buggy. In some 687 * situations, auto-mute will not deactivate when it should, so we want 688 * this feature disabled by default. An application (e.g. alsactl) can 689 * re-enabled it by using the controls. 690 */ 691 692 reg = cs4270_read_reg_cache(codec, CS4270_MUTE); 693 reg &= ~CS4270_MUTE_AUTO; 694 ret = cs4270_i2c_write(codec, CS4270_MUTE, reg); 695 if (ret < 0) { 696 dev_err(&i2c_client->dev, "i2c write failed\n"); 697 return ret; 698 } 699 700 /* Disable automatic volume control. The hardware enables, and it 701 * causes volume change commands to be delayed, sometimes until after 702 * playback has started. An application (e.g. alsactl) can 703 * re-enabled it by using the controls. 704 */ 705 706 reg = cs4270_read_reg_cache(codec, CS4270_TRANS); 707 reg &= ~(CS4270_TRANS_SOFT | CS4270_TRANS_ZERO); 708 ret = cs4270_i2c_write(codec, CS4270_TRANS, reg); 709 if (ret < 0) { 710 dev_err(&i2c_client->dev, "i2c write failed\n"); 711 return ret; 712 } 713 714 /* Initialize the DAI. Normally, we'd prefer to have a kmalloc'd DAI 715 * structure for each CS4270 device, but the machine driver needs to 716 * have a pointer to the DAI structure, so for now it must be a global 717 * variable. 718 */ 719 cs4270_dai.dev = &i2c_client->dev; 720 721 /* Register the DAI. If all the other ASoC driver have already 722 * registered, then this will call our probe function, so 723 * cs4270_codec needs to be ready. 724 */ 725 cs4270_codec = codec; 726 ret = snd_soc_register_dai(&cs4270_dai); 727 if (ret < 0) { 728 dev_err(&i2c_client->dev, "failed to register DAIe\n"); 729 goto error_free_codec; 730 } 731 732 i2c_set_clientdata(i2c_client, cs4270); 733 734 return 0; 735 736 error_free_codec: 737 kfree(cs4270); 738 cs4270_codec = NULL; 739 cs4270_dai.dev = NULL; 740 741 return ret; 742 } 743 744 /** 745 * cs4270_i2c_remove - remove an I2C device 746 * @i2c_client: the I2C client object 747 * 748 * This function is the counterpart to cs4270_i2c_probe(). 749 */ 750 static int cs4270_i2c_remove(struct i2c_client *i2c_client) 751 { 752 struct cs4270_private *cs4270 = i2c_get_clientdata(i2c_client); 753 754 kfree(cs4270); 755 cs4270_codec = NULL; 756 cs4270_dai.dev = NULL; 757 758 return 0; 759 } 760 761 /* 762 * cs4270_id - I2C device IDs supported by this driver 763 */ 764 static struct i2c_device_id cs4270_id[] = { 765 {"cs4270", 0}, 766 {} 767 }; 768 MODULE_DEVICE_TABLE(i2c, cs4270_id); 769 770 /* 771 * cs4270_i2c_driver - I2C device identification 772 * 773 * This structure tells the I2C subsystem how to identify and support a 774 * given I2C device type. 775 */ 776 static struct i2c_driver cs4270_i2c_driver = { 777 .driver = { 778 .name = "cs4270", 779 .owner = THIS_MODULE, 780 }, 781 .id_table = cs4270_id, 782 .probe = cs4270_i2c_probe, 783 .remove = cs4270_i2c_remove, 784 }; 785 786 /* 787 * ASoC codec device structure 788 * 789 * Assign this variable to the codec_dev field of the machine driver's 790 * snd_soc_device structure. 791 */ 792 struct snd_soc_codec_device soc_codec_device_cs4270 = { 793 .probe = cs4270_probe, 794 .remove = cs4270_remove 795 }; 796 EXPORT_SYMBOL_GPL(soc_codec_device_cs4270); 797 798 static int __init cs4270_init(void) 799 { 800 pr_info("Cirrus Logic CS4270 ALSA SoC Codec Driver\n"); 801 802 return i2c_add_driver(&cs4270_i2c_driver); 803 } 804 module_init(cs4270_init); 805 806 static void __exit cs4270_exit(void) 807 { 808 i2c_del_driver(&cs4270_i2c_driver); 809 } 810 module_exit(cs4270_exit); 811 812 MODULE_AUTHOR("Timur Tabi <timur@freescale.com>"); 813 MODULE_DESCRIPTION("Cirrus Logic CS4270 ALSA SoC Codec Driver"); 814 MODULE_LICENSE("GPL"); 815